1. Field of the Invention
This invention relates to foam control. In one aspect, the invention relates to foam control in an aqueous, alcoholic fermentation process while in another aspect, the invention relates to foam control in an aqueous, alcoholic fermentation process using a polyalkylene glycol with high functionality.
2. Description of the Related Art
Foam generation is a major problem in the production of alcohol-based fuels produced through fermentation, e.g., sugarcane bioethanol. Propylene oxide (PO)/ethylene oxide (EO) diols have been used as foam control agents in these applications for many years. These antifoam agents, however, often exhibit low persistency which requires their repeated addition to the fermentation broth to keeping foaming under control. As such, a continuing interest exists for antifoam agents with higher persistency which means, in turn, that they can be used in less frequently thus simplifying the process and, possibly, lowering costs.